Spot rubber continued to explore further highs on Monday. RSS 4 improved to ₹133 (131.50) a kg, according to traders and the Rubber Board. The market strengthened tracking the gains in domestic futures and global trendsetters while the trend was mixed as ISNR 20 closed unchanged amidst scattered transactions. May futures flared up to ₹136.44 (132.47) on the Indian Commodity Exchange. RSS 3 (spot) firmed up to ₹123.27 (122.32) at Bangkok. May futures improved to ₹125.85 (124.03)on the Tokyo Commodity Exchange (TOCOM). Spot rubber rates (₹/kg) were: RSS-4: 133 (131.50); RSS-5: 130 (129.50); ISNR 20: 124 (124) and Latex (60% drc): 91.50 (90.50).